The primary aim of this research is to determine whether DBT+ suboxone (an opiate drug replacement) is an efficacious treatment for opiate addicts meeting criteria for Borderline Personality Disorder (BPD) and to analyze factors that influence efficacy in this population in order to improve the treatment. DBT, originally developed for chronically suicidal women with BPD, is a synthesis of behavior therapy strategies aimed at change and validation strategies aimed at acceptance, both held together by a set of dialectical strategies and underlying assumptions. DBT has been adapted for BPD substance abusers by the addition of 1) specific targets relevant to drug use, 2) a set of attachment strategies, 3) greater reliance on arbitrary reinforcers at treatment start, 4) weekly urinalysis, and, in the case of opiate addicts, 5) an opiate drug replacement program (suboxone, i.e., buprenorphine in combination with naloxone) plus DBT clinical management. The research proposed here is a two arm, multi-site randomized clinical trial comparing a one year treatment program of DBT + suboxone for BPD heroin addicted individuals to a one year program of standard drug counseling + suboxone. Drug counseling will consist of manualized individual sessions + group therapy. Participants in both conditions will be prescribed psychotropic medications following a standardized medication protocol developed specifically for BPD individuals. To minimize the effects of treatment allegiance on outcome, the study will be carried out at Duke University Medical Center and the University of Washington. An expert in DBT at the University of Washington will train, supervise and conduct adherence ratings on DBT therapists at both sites. A Duke expert in drug counseling will do the same for the drug counseling therapists at both sites. One hundred and seventy-two individuals (86 per condition) with opiate dependence and meeting criteria for BPD will be enrolled in a one-year treatment and a one-year follow-up assessment. Assessments measuring drug use, suicidal behaviors, retention and other treatment related behaviors, general psychopathology and functioning, and increases in behavioral skills will be given at four-month intervals for the entire two years. Results will be analyzed using HLM and other regression based procedures.